la fehr



lI:A E. LA FEHH, E. IVI. HITCHCOCK AND H. V. LEAHY.

CARBURETER.. APPLICATION FILED AUG.2-I IQIY-i. RENEWED OCT. 5, 1920. 1h35? IQHWT Patented May 3J, 192k v 3 SHEETS-SHEET 2- llgd l?? 2 UNITED STATES TENT OFFIQE.

FRANCIS E. LA FEHR, EDGAR M. I-ITCI'ICOCK, .AND HERBERT V. LEAHY, OF LOS ANGELES, CALIFORNA.

CARBURETER.

Specification of Letters Patent.

Patented May 3, 1921.

Application filed August 21, 1917, Serial No. 187,358. Renewed october 5, 1920. Serial No. 414,830.

To all whom t may concern:

Be it known that we, FRANCIS E. LA Fin-m, llneAr. M. HITCHCOCK, and flnnnnn'r V.

'LEM-rv, citizens of the United States, residing at Los Angeles, in the .county of Los Angeles and State of California, have invented a new and useful Carbureter, of which the following` is a specification.

This invention pertains to devices designed to produce combustiblemixtures of air and fuel and an object of the invention is to produce a uniform mixture at all times for any particular degree of opening of the throttle valve.

Another object is to produce a mixture having the desired proportions of fuel and air for obtaining the best results in. power in accordance with the degree of engine suction and degree of opening of the throttle valve.

Another object is to so construct the device that the desired ends may be obtained Vwithout it beino necessar to em lo a float valve. Y

Jfinother object is to cause a maximum breaking up or atomizing of the fuel particles and to disperse said fuel particles uniformly throughout a stream or column of air.

Other objects and advantages will appear in the subjoined detail description.

The accompanying drawings illustrate the invention Figure 1 is a side elevation of an internal combustion engine equipped with the invention.

Fig. 2 is a diagrammatic view illustrating the electrical wiring.

Fig. 3 is an enlarged side elevation of the carbureter shown in Fig. 1.

4 is a vertical mid section of the can burcter shown in Fig. 3 taken on a plane at right angles to the direction of sight.

F 5 is a sectional View analogous to Fig. 4 showing the operating parts in dif` ferent positions than in Fig. 4.y Y

Fig. 6 is a plan section on line indicated by @0G-036, Fig. 4.

Fig. 7 is a plan section on line indicated by 007-507, Fig. 4.

Fig. 3 is an enlargedvertical section of the tubular member, stop forming sleeve and lock nut shown in Figs. 4 and 5.

Fie'. 9 is an enlarged fragmentary view of the fuel valve, stem, guide, nut and wnasher and spring on the stem, a fragment or the bridge, and a fragment of the distributer, all being in section excepting the valve and its stem.

Fig. 10 is an enlarged elevation of the distributer shown. in Figs. 4 and 5.

Fig. 11 is an enlarged side elevation of the inlet member shown in Figs. 4 and 5.

Fig. 12 is an enlarged vertical section of the valve seat member shown in Figs. 4 and 5.

Fig. 13 is a perspective view of the bushing shown in Figs. 4 and 5.

Fig. 14 is a sectional detail of a modified plunger, valve chamber, distributer and valve.

Fig. 15 is a perspective view of the upper end of the valve chamber and the valve abutment and its parts shown in Fig. 14.

First referring to Figs. 3 to 13 inclusive, there is provided a tubular member or tube 1 having one endv open to form a -miXture outlet 2 and having its opposite end closed by a plug 3 which may be screwthreaded into the tubular member 1 or otherwise suitably fastened in place. Near one end of the tubular member 1 adjacent the plug 3 is an air inlet 4 which may, if desired, be connected with any suitable source of hot air supply, not shown. lThe volume of miX- ture passing through the outlet 2 may be c ntrolled by a suitable throttle valve 5 mounted on a shaft t3 and provided with an. arm i for turning the shaft so as to open and close the throttle valve.

rlhe plug 3 is provided with a fuel passage 3 which extends upward inside of the carbureting chamber 1 through a tubular member 9 which, in the instance shown, forms a portion of the plug 3. rlhe upper end of the tube 9 terminates ina valve, seat .10 and said passage 8 may be closed by a valve plug 11 adapted to close onto the seat 10 as shown in Fig. 4 of the drawings. rlhe valve, inthe instance shown, is constructed of four differently shaped portions, a portion 12 of less diameter than the passage 8, which, when the valve is closed, extends a distance into the passage to aid in centering the valve 11; a frusto-conical portion 13 of comparatively great taper; a frusto-conical lfor the valve 11. Vis stationarily mounted and in the instance portion 14- of comparatively slight taper; and a straight cylindrical portion 15; and the valve is provided with a stem 16 having a reduced portion 17 that passes through a tubular guide '18 projecting through a bridge 19. At the inner end of the reduced portion 17 is formed a shoulder 2G and resting against said shoulder is a washer 21 and resting on said washer is a coil spring 22 which surrounds the inner end of the guide 18 between the bridge 19 andthe washer 21 so as to tend to hold the valve 11 down on its seat 10 when a shoulder 21 of the guide 18 is spaced Vfrom the bridge 19 which is shiftabley as will be explained hereinafter. Tfhe outer end of the reduced portion V17 of the valve stem is screw-threaded at 23 to receive a nut 24.

The bridge 19 forms a detachable portion of a hollow or tubular plunger indicated in general by the character 25 and being fastened in place by screws 25 or equivalents. The plunger 25 inthe instance shown in the drawings comprises a seat member 26 having a reduced portion 27; and also comprises a barrel 28 screw-threaded onto the reduced portion 27 5 and also comprises a hollow inlet member 29 screw-threaded into the barrel'28 and havin@ ports 30 whereby air may pass into the interior of the Vplunger 25.

At one end the inlet member 29 is provided with a bushing 31 which slides upon and is guided by a tubular member 32, the lower portion of said tubular member surrounding the tube 9 and having a portion lspaced from said tube.) and tlie'upper portionrof the member 32 above the upper end of the tube 9 forming a valve chamber 33 The tubular member 12 shown in the drawings is screw-threaded at 34 on the upper end of the tube 9, there being an annular shoulder 34 in the tubular member 32 against which the tube 9 seats. lvl/hen the plunger25 is in its lowered .position in Fig. 1 the bushing 31 rests upon an annular shoulder 32 on the outH side of the tubular member 32, and the inlet member 29 is'spaced from a shoulder or abutment on the outside of the bushing 31 which is loose in the inlet member.

At the upper end of the tubular member 32 is a distributer 36 which is screw-threaded or otherwise fastened to the tubular member. rThe distributer 86 is substantially cone shape with smaller end directed up and forms with the seat member 26 an air valve adapted when the plunger 25 is in closed position to seat at 37 in the seat member 26 so as to prevent passage of air through the plunger 25.

When the seat 37 rests on the distributor the plunger is supported entirely by the distributer, the spring 18 is compressed slightly and the washer 21 is spaced slightly from the upper end of the distributer.

The fuel distributer 36 is provided with numerous durts or perforations 38 and said perforations preferably extend at right angles to the axes of the distributer and plunger so that fuel sprayed from the perforations will be directed iifto the column of air passing through the plunger substantially transverse to the direction of flow of said air so as to obtain maximum breaking up or atomizing of the fuel and therefore uniformity of distribution of the fuel particles throughout the column of air. The valve stem 16 passes through the distributer 36 centrally thereof and the distributer is chambered at 39 to form an extension of the chamber From the foregoing it is clear that y a. continuous fuel passage is formed by the combined passage S and chambers 33 and 39, and fuel conducted to the passage 8 through a fuel supply line indicated fragmentarily at L10.

Freferably the distributer 36 is provided with annular grooves 77 communicating with the outer ends of the ducts 3S and the advantage of these grooves is that some of the fuel runs along the grooves and is thus distributed circumferentially of the distributer so as to effect as far as possible a uniform distribution of the fuel lo all portions circumferentially of the column of air flowing past the distributer.

t is noted that the seat 37 is tapered or beveledL and that the taper corresponds with the taper of the periphery of the distributer. rfhe advantage of this is that air passing upward through the plunger 25 will be di rected by the taper seat 37 parallel to and directly in Contact with the periphery of the distributer so as to spread the fuel over the periphery of the distributer before said air takes up the fuel. thus to break up the fuel as finely as possible by friction of the air thereon.

An adjustable stop is provided on the tubular member to limit upward movement of thI plunger 25 and said stop, in the instance shown, is formed by the lower end of sleeve 4-1 surrounding` the tubular member 32 and screw-threaded thereon at ft2, there being a lock nut i3 screw-threaded onto the tubular member 232 against the sleeve to lock it in adjusted position. Adjustment of the sleeve 41 along the member l2 will determine the amount of movement to which the plunger may be subjected because the bushing 31 is in line with the sleeve L11 so as to engage the same when the plunger is moved upi'ard suiliciently far to bring about the engagement. The weight of the plunger and the falve 11 tends to resist upward movement of the plunger, and the resistanee is increased by reason of there being a coil spring e4 surrounding the tubu` lar .member 32 and having one end resting against the bushing 31 and having the other end resting against the distributer 36.

Thus it is clear that `the cross sectional area of the passage betweenthe distributer 36 and plunger member 26 is dependent on the degree of suction established in the tube 1. above the plunger:

The inlet end of the seat member 26 is outwardly expanded at 80 and has a straight portion 81 between the seat 37 and the eX- panded portion, and the space between the inlet member 29 and abutment 65 is slightly greater ythan the length of the straight portion 81, when the plunger is in its lowered position, so that when the plunger is raised to just cause engagement of the inlet member with the abutment the expanded portion 8O will come opposite the large end of the distributer and thus produce an annular space between the'seat member 26 and distributer so that air can pass from below the distributer to the space above said distrib-uter. v

The tube 9 is provided externally with insulation and around this is placed a resistance coil 46 adapted to receive electric currenty from any suitable source of supply. In Figs. 1 and 2 of the drawings the resistance coil 46 is vgrounded at one end to the tube 9 andy has its other end connected by a lead 47 to a binding post 48 of a thermostat 49. This thermostat may be of any suitable construction and is shown as being provided with a standard 50 on which the binding post 48 is mounted, there being a contactV screw 51 to engage a thermostat leaf or vleaves 52 mounted on a base 53. The bracket is insulated at 54 from the base and said base is provided with a binding post 55 connected by a lead56 to a suitable source of electric current supply 57. The electric current supply 57 is provided with a lead 58 which is electrically connected by any suitable means to the tube 9 and in the instance shown in Figs. 1 and 2 of the drawing said lead is grounded to an engine 59 which is equipped with the carbureter above described, the intake pipe 60 of the engine be.- ing connected to the outlet 2 and the air inlet 4 being connected by a pipe 61 to an air heater 62 mounted on the exhaust pipe 63 of the engine. The thermostat 49 is mounted on the exhaust pipe 63.v When the engine is cold the thermostat is closed as shown in Figs. 1 and 2 so as to cause a Acurrent of electricity to fiowl through -the resistance coil 46, thereby heatingv the tube 9 and the fuel therein so as to facilitate gasification when the Vengine is statredinto operation. When the engine heats up the heat radiated from the exhaust pipe causes the thermostat to open the circuit so that the resistance coil 46 will no longer ybe energized.

Outsidefof` the coil 46 maybe placed an insulation sleeve 64. The insulation 45, 64 and coil 46 are accommodated in the space between the lower portion of the tubular member 32 and the tube 9.

In practical operation when it is desired t0 start the engine into operation, the throttle valve 5 will be opened slightly and the engine will be turnedover by hand or any other means well known in the art and the suction produced in the engine cylinders thereby will cause the plunger 25 to rise until the inlet member 29 engages a shoulder 65 on the bushing 31. At idling speeds the power of the spring 44 is sufficient to prevent further upward movement of the plunger 25, but said plunger has moved sufficiently to allow a comparatively small volume of air to pass between the seat member 26 and distributer 36 as above explained, and the upward movement of the plunger' has also raised the fuel valve 11 from its seat to permit fuel to be sucked from the passage 8 into the chamber 33, thence intothe chainber 39 and outward through the perforations 38 so as to atomize or spray the fuel into the column of air passing upward around the distributer 36, thus producing a mixture of air and fuel that is substantially uniform throughout as regards the proportion of fuel and air.

It is noted that owing to the ducts 38 being directed toward the column of air at an angle to the direction of flow of the air the fuel sucked from the ducts and thereby reduced to small particles will be still further broken up by friction of the air against said particles, thus attenuating the fuel to such a degree as in effect to vaporize and partly gasify the fuel since .it becomes invisible and cannot be apprehended byV the'sense of touch.

`When it is desired to speed up the engine the throttle valve 5 will be opened farther thus increasing the degree of suction in the upper portion of the carbureting tube 1, and this increased suction will cause the plunger 25 to move still farther away from the distributer 36 so as to allow a greater volume of air to How past said valve. Coinci-\ dentally the plunger 25 will raise the fuel valve 11 still further without however, admitting more fuel until the portion 15 of valve comes adjacent a slightly expanded portion a of the chamber 33, whereupon there is admitted a greater volume of fuel to the perforations 38 to supply the increased volume of air with an increased amount of fuel.

Further opening of the throttle valve successively brings the valve portions 14, 13 respectively adjacent the passage portion a so as to admit more and more fuel to the ducts 38. From this it is clear that owing to the particular construction of the valve and the passage 33 there is first produced avery 4rich mixture for starting, and then a leaner mixture for higher speeds by increase of air and no increase of fuel, and finally a lean mixture suitable for still higher speeds since both the air and fuel volumes are increased proportionately.

During operation of the engine the plunger 25 floats in the tube 1, rising and falling with every variation in the requirements of the engine and degree of opening of the throttle valve 5 so as to increase and diminish the volume of mixture supplied to the engine through the outlet 2 and at times to vary the proportions of fuel and air.

Inthe modification shown in Figs. 14 and 15 the valve is indicated at 66 and is of similar construction to the valve 11 excepting that there is no valve stem, suction being relied upon to directly open the fuel valve instead of' indirectly by way of the plunger which is indicated at 67. rlhere Vis no valve seat in the plunger 67 as inthe plunger `25 but when the parts are in the position shown in Fig. 14 a comparatively small volume of air passes between the plunger 67 and distributer 68. This distributer is closed at its upper end, since there is no valve stem passing therethrough andV said distributer is screw-threaded onto the upper end of a tubular member corresponding to the tubular member 32 and indicated by the same reference character, `said tubular member being screw-threaded on the upper end of a tube corresponding to the tube 9 and indicated by the same reference character.

When the. device shown in 11i is subject toy comparatively slight suction, the plunger 67 rises slightly and the fuel valve 66 is raised by the suction so at to admit Vfuel to the perforations 69 of the distributer. When the device is subject to greater suction the plunger 67 will rise suiiiciently to cause the tapered portion 70 thereof to come adjacent the lower portion of the distributer valve 68 so as to admit a greater volume of air to pass the valve, and the increased suction will'cause the valve 66 to raise an abutment 71 against the pressure of a spring 7 2 so as to admit more fuel to the perforations 69 of the'distributer. The spring 72 surrounds a stem 73 fastened to the abutment 71 and said stem is provided with a nut 74 which limits downward movement of the abutment 71 caused bythe spring 72. The upper end of the spring 72 rests against a vbridge 75 and the ends of said bridge rest in notches 76 in the upper end of the tubular member 32.

The further operation of this modified form of the invention will be readily understood from the foregoing description of the operation of the device shown in Figs. 1 to 13 respectively.

In the form of the invention disclosed in Figs. 1 to 13, if the engine back-fires it is clear that the plunger will be driven downward by the force of the explosion to close the seat 37 on the distributer so as to shut off the air, whereupon combustion can no longer be supported in the carbureter.

it is understood that the degree of taper of the valve portion and the tube portion a is more or less exaggerated in the drawings, but in actual practice the taper will be very slight.

Vile claim:

1. 1n combination, a chamber having an inlet and an outlet, a tubular member having an annular shoulder and having an adjustable stop spaced from the annular shoulder, a plunger surrounding the tubular member, a bushing loose in the lower end of the plunger between the shoulder and stop and having an abutment to engage the plunger, a hollow perforated distributor on the upper end of the tubular member, and a spring between the distributor and bushing.

2. ln combination, a chamber having an inlet and an outlet, a tubular member having an annular shoulder and having an adjustable stop spaced from the annular shoulder and having a valve seat, a plunger surrounding the tubulaimember, a bushing loose in the lower end of the plunger between the shoulder and stop and having an abutment to engage the plunger, a hollow perforated distributer on the upper end of the tubular member, valve in the tubular member to close on the valve seat, means connecting the valve to the plunger, and a spring between the distributer and bushing.

3. ln combination, a chamber having an inlet and an outlet, a fuel passage in said chamber, a cone-shaped hollow distributer at the upper end of the fuel passage provided with radially extending ducts, said distributer being provided in its periphery with annular grooves communicating with the outer ends of the ducts, and a hollow plunger surrounding the distributor and adapter to float in the chamber when suction is applied to the chamber above the plunger.

el. ln combination, a chamber having an inlet and an outlet, a fuel passage in vsaid chamber having a valve seat therein, a concshaped hollow distributer at the upper end of the fuel passage provided with radially extending ducts, said distributer being provided in its periphery with annular grooves communicating with the outer ends of the ducts, a hollow plunger surrounding` the distributer and adapted to float in the chamber when suction is applied to the chamber above the plunger, and a valve in the fuel passage to close on the seat and connected with the plunger to be operated thereby.

5. in combination, a chamber having an inlet and an outlet, a tubular member in said chamber having a valve seat therein, a hollow perforated distributer at the upper end of the tubular member, a hollow plunger in the chamber surrounding the distributer and provided with a bridge and provided with a seat to engage the distributer, a valve in the fuel passage to close on the seat and provided with a stem extending through the distributer, there being a shoulder on the stem, a valve resting against said shoulder, a tubular guide on the stem above the washer and extending through the bridge and having a shoulder to engage the upper face of the bridge, a spring surrounding the guide between the 'washer and bridge, and

a nut on the stem to engage the outer end of the guide, the washer being spaced from the distributer and the shoulder of the guide being spaced from the bridge when the valve is seated and the seat of the plunger is resting on the distributer.

6. In combination, a chamber having an inlet and an outlet, a tubular member in said chamber having a valve seat therein, a hollow perforated distributer at the upper end of the tubular member, a hollow plunger in the chamber surrounding the distributer and provided with a bridge, said plunger including a seat member to close onto the distributor provided with a seat, and with a downwardly expanding inlet, there being a straight portion between the seat and inlet, a bushing surrounding the tubular member and provided with a shoulder to be engaged by the plunger, a spring between the bushing and the distributer, a stem for the valve passing through the distributor, and means connecting the valve to the bridge, the space between the plunger and the shoulder of the bushing being slightly greater when the plunger is in lowered position than the length of the said straight portion of the seat member.

7. In combination, a tube, a tubular plunger in the tube, a bridge over the upper end of the plunger, a tubular member extending up inside of the plunger and provided with a valve seat in its interior, a valve to close on said valve seat, a stem for the valve eX- tending through the bridge and provided with a shoulder, a nut on the upper end of the stem, a tubular valve guide between the sho ulder and nut having a shoulder adapted to be engaged by the bridge in the upward movement of the plunger, a spring between the bridge and stem shoulder to tend to hold the valve on its seat when the shoulder of the tubular guide is spaced from the bridge, a valve seat in the inside of the plunger, and a perforated distributer on the upper end of the. tubular member around the valve stem adapted to be engaged by the valve seat of the plunger when the plunger is in its lowermost position.

8. In Combination, a tube, a hollow plunger in the tube, comprising a seat member and a barrel screw-threaded onto the seat member and a hollow inlet member screwthreaded into the barrel, there being ports in the peripheral wall of the inlet member, a tubular member having a valve seat and having an abutment on its periphery and having its upper end inside of the plunger, a perforated distributer on the upper end of the tubular member, a spring having one end resting against the abutment and the other end against the distributer, and a valve inside of the tubular member to engage the valve seat to control the flow of fuel.

Signed at Los Angeles, California, this 14th day of August, 1917.

FRANCIS E. LA FEHR. EDGAR M. HITCHCOCK. HERBERT V. LEAHY.

Witnesses:

GEORGE H. HILES, A. F. SOHMIDTBAUER. 

